Article stacker



E. C. OLSON ARTICLE STACKEE July 29, 1969 5 Sheets-Sheet 1 Filed March 6, 1967 E. c. OLSON 3,458,059

ARTICLE STACKER July 29, 1969 5 Sheets-Sheet 2 Filed March 6, 1967 J22 %d/m .252: g

E. C. OLSON ARTICLE STACKER July 29, 1969 5 Sheets-Sheet 5 Filed March 6, 1967 fizzan t 42F [06/12 C OLSON July 29, 1969 Filed March 6, 1967 E. c. OLSON I 3,458,059

ARTICLE STACKER 5 Sheets-Sheet 4 .Zfizazztar 06248 6. 0.49am

July 29, 1969 E. c. OLSON 3,458,059

ARTICLE STACKER Filed March 6, 1967 5 Sheets-Sheet 5 Jzzzazz 47.? [2642 6 OLSON United States Patent 3,458,059 ARTICLE STACKER Edgar C. Olson, Waukegan, Ill., assignor to National Dairy Products Corporation, Chicago, 11]., a corporation of Delaware Filed Mar. 6, 1967, Ser. No. 620,819

1 Int. Cl. B65g 57/00 US. Cl. 2146 19 Claims ABSTRACT OF THE DISCLOSURE The arrangement of units into stacks, in which each unit is delivered to a slot adjacent the periphery of a rotating frame, maintained in the slot until a predetermined rotative position has been reached, and then allowed to fall from the slot into a pocket adjacent the axis of rotation of the frame where it assumes a stack form with other units falling into the same pocket.

The present invention relates to the arrangement of units in stacks and has for its principal object the pro vision of an improved method and apparatus for accomplishing such an arrangement.

Other objects and advantages of the invention will become apparent with reference to the following description and the accompanying drawings.

In the drawings:

FIGURE 1 is a fragmentary elevational view of an apparatus showing various of the features of the invention;

FIGURE 2 is an enlarged fragmentary partially broken-away elevational view of a portion of the apparatus shown in FIGURE 1;

FIGURE 3 is a fragmentary sectional view taken along line 3-3 of FIGURE 1;

FIGURE 4 is a fragmentary sectional view taken along line 4-4 of FIGURE 2;

FIGURE 5 is a perspective view of a portion of the apparatus shown in FIGURES 1 through 4; and

FIGURE 6 is a fragmentary end view of the apparatus of FIGURE 1 looking in the direction of the arrows 66 of that figure.

Very generally, in the illustrated embodiment of the invention there is shown an apparatus 10 for arranging units 12 in a stack. The apparatus is adapted to receive a continuous succession of the units 12, which are preferablyfed continuously one after the other in a row. The apparatus illustrated actually receive units from two supply columns and produces two stacks simultaneous. However, the operation of the apparatus is illustrated as well by the formation of one stack as two and only the structure employed to form a single stack will be described completely.

The apparatus 10 includes a conveyor 14 which receives the units from a supply source and delivers them to a stacker 16. The stacker 16 arranges the units in stack form and delivers the stacks to a discharge conveyor 18 which conveys them to a subsequent processing station (not shown).

The illustated apparatus is particularly useful in the stacking of individually wrapped slices of cheese such as are produced by the method and apparatus disclosed in U.S. patent application Ser. No. 550,234, filed May 16, 1966. A reference to such method and apparatus, as well as to the individually wrapped slices produced thereby, is believed helpful to a clear understanding of the present invention. However, it is to be understood that the invention is not restricted to the stacking of such units, and that such units are referred to herein to facilitate the following description and not by way of limitation.

As set forth in the above-referred-to application, the Wrapping of the individual slices of cheese is accomplished by forming a tube of wrapping material around the slices as the slices move in a row along a given path. The tube is subsequently sealed between the individual slices and then severed at the seal to form individual packages. These packages are flat, generally planar, and readily stackable. The severing of the tube intermediate the slices is accomplished by passing the tube between a pair of rotating rolls, one of which carries one or more knife blades and serves as a cutting roll and the other of which serves as an anvil which cooperates with the knife blades. Such rolls are represented in FIGURE 1, the cutter roll being designated by the numeral 20, the knife blades by the numeral 21, and the anvil by the numeral 22. In FIG- URE 1, a package or unit 12 can be seen emerging from between the rolls as it is being severed from the remainder of the packaging tube. A portion of the tube, designated by the numeral 23, is shown entering the nip of the rolls 20 and 22.

After being severed from the tube 23, the individual packages or units 12 fall by gravity into an arcuate chute 24 which delivers them to the conveyor 14. The conveyor 14 comprises an endless belt 26 which is supported by rolls or drums 27 carried on a frame 27a pivoted about the axis of the roll farthest from the stacker 16. An adjusting bracket 27b supports the opposite end of the frame and permits precise positioning of the upper run of the conveyor to achieve accurate timing of the units 12 relative to the stacker. Preferably, the upper run of the conveyor is disposed at an inclination to the horizontal of approximately 20 so as to cause the upper run to lie in a plane which contains the axis of rotation of the stacker 16.

Positioned within the loop of the conveyor belt 26 is a vacuum housing 28 (FIG. 2) connected to a suitable vacuum source (not shown) and having an upper wall 30 provided with a pair of longitudinally extending channels 32, the bases of which are provided with a plurality of openings 34. The openings 34 therefore lie in the channels beneath the belt and are not closed by the belt but rather continuously provide communication between the interior of the vacuum housing and the channels. The conveyor belt 26 is likewise provided with a plurality of openings 35 which align with the channels 32 so that a continuous vacuum is maintained adjacent the upper run of the belt 26 effective to maintain the position of the units on the belt. The channels 32 terminate short of the delivery end of the belt so that as the individually wrapped cheese slices approach the end of the belt they are no longer retained on the belt by vacuum and will enter the stacker 16 as hereinafter described.

It will be noted that the belt 26 is caused to travel at a somewhat faster speed than the tube 23 soas to effect a spacing between the units on the belt 26, as seen in FIG- URE 1.

In general, the stacker 16 is in the form of a rotatably mounted wheel having a number of pockets 36 adjacent its hub (FIG. 3) and a greater number of slots 38 adjacent its periphery, each pocket being in communication with a plurality of slots. A stationary shelf 40 is provided and is located so as to be intermediate some of the pockets and the slots in communication with those pockets at all times. When the shelf is intermediate any given pocket and its associated slots, it precludes the passage of units 12 from the slots into the pocket. As the wheel rotates, pockets move out of proximity to the shelf, re-establishing communication between the pocket and its slots, while other pockets move into proximity to the shelf so that, as to them, communication is temporarily blocked. In the illustrated embodiment, the shelf 40 spans approximately four and one-half. pockets and extends from the 9 oclock position (when viewing the stacker rotating in a clockwise direction) to between the 12 oclock and 1 oclock positions.

Units to be stacked, such as the packages 12, are delivered to the stacker wheel and enter the slots 38 at a point slightly below the oclock position. As the wheel rotates, the units slide radially inwardly within the slots until they engage the shelf 40, which temporarily precludes their entry into the associated pocket 36. When the units reach the point of shelf termination, however, i.e., the 12 oclock- 1 oclock position, at which point they are slightly inclined to the right of the vertical, they fall inwardly into the pocket. This point of termination of the shelf has been found to be particularly conducive to the units arranging themselves in a stack within the pocket. When the pocket reaches a predetermined rotative position, approximately the 3 oclock position, the stack is ejected from the pocket onto the conveyor 18.

Referring now more particularly to FIGURE 3, the stacker wheel 16 includes a frame 44 supporting horizontally spaced bearings 46 within which a shaft 48 is mounted for rotation about a horizontally disposed axis. Secured to the shaft 48 for rotation therewith is a hollow hub 50, and bolted to the opposite end faces of the hub are end plates 52 and 53, each of which includes an outwardly projecting cylindrical flange 54. The end plates are arranged on the hub 50 in generally parallel relation to each other. The flanges 54 project outwardly away from each other in encircling relation to the opposite ends of the shaft and serve at least partially to support the units 12 during a portion of their travel with the stacker wheel, as will hereinafter become apparent.

The end plate 52, the left hand plate as the stacker wheel is viewed in FIGURE 3, has bolted to it adjacent its periphery a large ring gear 56 having a large central opening which enables it to encircle the hub 50 as well as various elements supported on the hub. The ring gear 56 also affords a means whereby a large ring segment 58 is attached to the outer periphery of the end plate 52 so as to constitute an extension thereof. A similar ring segment 60 is bolted to the opposite or right hand end plate 53 by means of an annular mounting ring 62.

The ring gear 56 is therefore rigidly connected to the hub 50 and rotates therewith. The gear 56 is in meshing engagement with a pinion gear (not shown) driven through various gear reductions (not shown) by a suitable power source (not shown). The same power source preferably drives a gear 64 (FIG. 1) through suitable gear reductions, the gear 64 being connected to and effective to drive the conveyor belt 26. Thus, the conveyor belt 26 and the stacker wheel 16 are mechanically linked and driven in timed relation to each other.

That area of the stacker wheel located adjacent to and radially outwardly from each of the cylindrical flanges 54 is divided into the pockets 36 by a plurality of inner fins 68 which are disposed in grooves provided in both the outer cylindrical surface of the flanges 54 and in the outer faces of the end plates 52 and 53. The inner fins 68 are preferably secured in place by welding and are positioned so as to be radially directed, i.e., so as to lie in planes containing the axis of rotation of the stacker wheel. In the illustrated embodiment, fifteen inner fins 68 are employed to divide the wheel into fifteen pockets 36 of equal size. The pockets 36 on opposite sides of the wheel are in alignment with one another.

It will be noted that while the units are in the pockets, they rest upon both the flange 54 and partially upon the leading fin 68 of the pocket, i.e., the fin of the pocket which precedes as the wheel rotates. At the time the stack is discharged, however, it is supported principally by the leading fin, which thus serves as a platform for the stack. The central portion 70 of each fin is offset in the leading direction (FIG. 2), thereby providing contact be tween the platform and stack along two narrow surfaces rather than a single wide surface. In addition, the upper corners of each fin are cut away: the corner nearest the center of the stacker wheel is cut away, as at 72 (FIG. 3), to accommodate a portion of an upper fin 82 soon to be described; the corner adjacent the outer face of the wheel is cut away, as at 75, to accommodate a guide 76. A notch 78 is also provided in the outer edge of the fin approximately midway of its height to accommodate a second guide 80. The guides 76 and 80 are positioned beneath the shelf 40 and guide the units into proper arrangement Within the pockets.

In addition to the supporting shelf 40 and guides 76 and 80, a stationary curved guide plate 81 is provided above the shelf 40. The plate 81 is generally triangularly shaped (FIG. 3) and includes an inclined edge 81a which slants inwardly from left to right. Units which engage the plate 81 are shifted inwardly as they are moved past the plate, thereby assuring alignment of the units prior to their entry into the pockets 36.

The slots 38, which are in communication with the pockets 36, are defined radially by outer fins 82, each of which is received and welded in place within a groove in one of the ring segments 58 and 60. Additional support for the fins, as well as an outer boundary therefor, is provided by a rod 84 bent into an annular shape and welded to the outer edges of all of the fins 82. The fins 82, like the fins 68, are also radially directed and are more numerous than the inner fins 68. In the illustrated embodiment, eight outer fins are provided for each inner fin, so that eight slots 38 are provided for each pocket 36. Each fin 82 is embossed to provide four ribs 86 which extend in a leading direction, and each is generally rectangular except for a downwardly extending ear 88 adjacent its lower inner corner which occupies the space 72 provided by the removal of the inner upper corner of the fins 68. Thus, a portion of each fin 82 extends into each pocket 36.

The operation of the stacker wheel, insofar as the formation of the stack of units within a pocket 36 is concerned, can now be readily understood. With reference to FIGURE 1, a unit 12 is delivered into each slot 38 in the wheel 16 as the wheel passes the delivery end of the belt conveyor 26. The movement of the belt and the wheel are in timed relation to each other, and the vacuum at the upper surface of the belt is utilized, to insure proper sequential delivery of the units. The conveyor has been phased with the stacker wheel 16, if necessary, by raising or lowering the conveyor by means of the bracket 2711. It is to be noted that at the point of delivery, the upper surface of the belt 26 and the slot 38 positioned to receive the next unit lie in approximately the same inclined plane.

The unit enters each slot as the slot travels upwardly and, consequently, the units are moved by gravity along the slot inwardly of the wheel as the slot gradually assumes a more vertical position. Each unit eventually comes into contact with the shelf 40 which limits its inward movement and prevents it from entering the associated pocket 36. The alignment guide 81 forces the units inwardly to assure a properly aligned stack. When the slot 38 occupied by the unit reaches the termination point of the shelf 40, which occurs shortly after the unit has passed a position vertically above the axis of rotation of the wheel and is moving downwardly, the unit begins to drop by gravity and is guided by the guides 76 and 80, and then engages the flange 54. The first unit to reach the flange 54 of any given pocket is positioned adjacent the leading fin 68 of the pocket and rests against this fin (as opposed to the opposite fin of the pocket) by virtue of a downward movement of the pocket and leading fin. The second unit into the pocket engages the flange 54 and its lower edge portion rests against the first unit. The upper edge portion of this unit remains spaced from the preceding unit by the car 88 of the outer fin 82 which extends into the pocket 36. The units drop into the pocket in succession until all of the slots communicating with the pocket have been emptied. As the wheel continues to rotate, each pocket eventually assumes a position in which the leading fin is at an angle of approximately 6 above the horizontal, at which point the units, which are now in a generally vertical stack, slightly spaced along one edge by the ears 88, are discharged as a body onto the conveyor 18, the upper run of which is disposed at approximately the same angle above the horizontal.

It has been found that the units hold better stacks when the packaging material is moistened slightly, as by being given a light coating of a mineral oil. Accordingly, a suitable device (not shown) is preferably provided prior to the cutting of the tube to apply one or more strips of an oil film thereto.

As has been previously mentioned, the pockets 36 on opposite sides of the stacker wheel 16 are in alignment with one another. The stacks are simultaneously discharged from aligned pockets, and from the platform defining the pockets, by a pusher mechanism 90, one of which is provided for each pair of aligned pockets. The operation of the pusher mechanisms 90 is controlled by a stationary cam track 92 (FIG. 5). More specifically, each pusher mechanism comprises an elongated channel 94 positioned on the central portion of the hub 50 of the wheel 16 with its base 96 fastened to an upper cylindrical surface of the hub by recessed cap screws 98 (FIG. 3). The channel 94 includes upstanding side walls 100 (FIG. 2) which are flared outwardly adjacent their outer ends to widen the channel opening at that point. Positioned adjacent the base 96 for sliding movement within the channel 94 is a rack bar 102 disposed with its teeth facing upwardly. A vertically disposed pusher plate 103, which defines essentially the entire inner end wall of its associated pocket, is secured to one end of the rack bar 102 (the right hand end in FIGURE 3) and is located within a pocket 36. Positioned above the bar 102 and in meshing engagement therewith are three horizontally spaced pinion gears 104 mounted for rotation about pins 106 which pass through the channel walls 100 and are secured therein. Thus, it will be apparent that rotation of the pinion gears 104 will cause the rack bar 102 to be extended and, in so doing, to move the pusher plate 103 into and through the pocket 36. An opening 108 is provided in the end plate 52 to permit the rack bar 102 to pass through the plate, and the outer face of the end plate is recessed slightly to accommodate the pusher plate 103. Positioned above the pinions 104 and in engagement therewith is a second rack bar 110 disposed wi h its teeth facing downwardly and held in place within the channel 94 by retaining strips 112 (FIG. 2). A vertically disposed pusher plate 114 is secured to the outer end of the rack bar 110 and, like the plate 103, defines essentially the entire inner end wall of the associated pocket 36. The adjacent end plate 52 is provided with an opening 116 and is recessed to accommodate the bar 110 and the plate 114. A cam follower roller 118 is provided at the outer surface of the rack bar 110 (the upper surface in FIGURE 3) and engages the cam track 92 as the wheel rotates to effect reciprocating movement of the bar 110.

It will be appreciated that as the bar 110 reciprocates, the pusher plate 114 is moved through the associated pocket 36 and returns. Reciprocation of the bar 110 also effects reciprocation of the bar 102 through the pinion gears 104. Thus, both bars 102 and 110 reciprocate simultaneously, one in one direction and the other in the opposite direction. In FIGURE 3, the bars 102 and 110, as well as the pusher plates 103 and 114, are shown in their retracted positions whereas in FIGURE 4 they are shown in their extended positions.

Movement of the pusher plates 103 and 114, through movement of the racks 102 and 110, is effected by engagement of the roller follower 118 of each pusher mechanism with the cam 92. Thee cam 92 comprises a relatively large, somewhat annular structure supported by the frame 44. As seen best in FIGURE 5, the cam 92 is formed for convenience in two halves separated along a horizontal plane. The lower half is defined by a pair of generally vertically arranged horizontally spaced plates 120, each of which is of semi-annular configuration. The plates are interconnected by a triangularly shaped curved plate 122 which extends between the upper curved edges of the plates and defines a canted surface extending upwardly from right to left. Horizontally disposed oppositely directed flanges 124 are provided at the ends of the plates 120 to facilitate mounting of the cam 92 on the frame 44 and to facilitate interconnection of the upper and lower halves of the cam.

The upper half of the cam 92 is defined by a single semi-annular plate 126 having a generally horizontally disposed flange 128 at each of its ends which rest upon the flanges 124 of the lower half of the cam. A curved plate 130 is attached to and projects from the upper edge of the plate 126. In addition, a pair of adjustable cam brackets 132 and 134 are secured to the upper plate 126. Each of the adjustable cam brackets includes a curved and generally triangular plate 133 and 135 respectively, seen best in FIGURE 6.

As the stacker wheel 16 rotates, the cam follower 118 engages the outer surface (to the right in FIGURE 3) of the upper semi-annular plate 126 from a point where the follower is at approximately the 9 oclock position, upwardly until it reaches approximately the 12 oclock position. This portion of the plate 126 is flat and, accordingly, there is no reciprocation or movement of the rack bars 102 or 110 during such movement. At approximately the 12 oclock position, however, the plate 126 is cut away and the roller passes to the opposite side of the plate by virtue of an engagement with the adjustable cams 132 and 134 which are positioned in close proximity at that point and their edges define a groove bounded by camming surfaces on both sides. It will be noted (FIG. 6) that the adjustable cam bracket 134 includes a portion which projects outwardly past the surface of the plate 126 to intercept the roller follower 118 and direct it inwardly into engagement with the cam 132.

The groove defined by the cam brackets 132 and 134 guides the roller 118 downwardly and toward the left (FIGS. 36) into engagement with the upper portion of the right hand edge of the curved plate 122 of the lower half of the cam. During such movement, the rack bars 102 and 110 become extended. The edge of the plate 122 guides the roller downwardly and toward the right and then upwardly and toward the right back to the outer surface of the plate 126. Thus, the roller 118 moves from right to left and back as the stacker wheel 16 completes one revolution. It will be appreciated, of course, that the camming surfaces are arranged, or can be adjusted, so as to effect the desired movement of the pusher plates 103 and 114. In the illustrated embodiment, these plates are in a retracted position from approximately the 9 oclock to slightly past the 12 oclock position, at which point the ejection stroke begins. The ejection stroke is completed shortly before the wheel 118 arrives at the 3 oclock position, and the pusher plates are fully retracted again when the roller reaches the 9 oclock position.

At shortly before the 3 oclock position, the pusher is located above the conveyor 18. When fully extended, it still does not project past the side of the wheel 16 and does not engage the conveyor 18. However, the timing of the pusher is such that as the stack ceases to be supported by the wheel 16, it receives support from the conveyor 18.

The conveyor 18 is shown best in FIGURE 1 and comprises generally an endless chain 136 supported by sprockets 138 between rails 139 to which the stacks are delivered (FIG. 4). A finger 139a is pivoted to one of the rails 139 and spans the gap between the rails so as to support the stacks as it moves across the gap. The finger is biased to a spanning position. The chain 136 is provided on its upper surface with pusher plates 140 which project outwardly from the chain and serve to engage the stacks as they rest on the rails. The Pusher moves the finger 139a out of the way as it passes. As previously mentioned, the upper run of the belt is at a slight inclination, e.g., 6, to the horizontal.

While the stacks are moving on the conveyor, they are preferably compressed vertically, i.e., subjected to a downward force normal to the planes of the units. This may be accomplished by passing the stack under an overhead compression conveyor (not shown). The compressing of the stack serves to bring the units into intimate contact and permits the oil coating applied to the-surfaces of the wrappers to create a surface tension between wrappers effective to unite the units and cause them to adhere to one another.

An improved method and apparatus have thus been described for arranging articles or units in stack form. While the invention has been shown with respect to one specific embodiment, it should be apparent that various modifications may be made therein without affecting the scope of the invention.

Various features of the invention are set forth in the following claims.

What is claimed is:

1. An apparatus for arranging units in a stack, said apparatus comprising a frame mounted for rotation about a generally horizontal axis, means for effecting rotation of said frame about said axis, means on said frame defining pockets extending radially outwardly from adjacent the axis of rotation of the frame, means on said frame defining a plurality of slots extending radially inwardly from adjacent the periphery of the frame into communication with each of said pockets, means for successively delivering a unit into each of said slots as the outer end thereof moves upwardly past a given station located above the axis of rotation of said frame and adjacent the periphery thereof, and means precluding movement of a unit from its slot into the pocket with which it communicates until the unit has been carried to a position in which it is essentially directly above the axis of rotation of said frame, said latter-mentioned means permitting free fall of the units in rapid succession from said slots into stack form within said pockets as the units leave said position.

2. An apparatus in accordance with claim 1, wherein each of said slots lies generally in a plane containing the axis of rotation of said frame.

3. An apparatus in accordance with claim 1, wherein said means for precluding movement of a unit from its slot comprise a shelf supported so as to be stationary relative to said frame.

4. An appropriate in accordance with claim 3, wherein said shelf is positioned so as to be intermediate each pocket and at least some of the plurality of slots in communication therewith over a portion of the path traversed by each as the frame rotates.

5. An apparatus in accordance with claim 4, wherein said shelf is of an arcuate configuration and is positioned so as to define a supporting surface which partially encircles the axis of rotation of said frame and is spaced therefrom a distance closely approximating the radius of its arc.

6. An apparatus in accordance with clai 1, wherein means are provided for contacting the stack within each pocket and discharging it therefrom as the pocket reaches a predetermined rotative position relative to the axis of rotation of the frame.

7. An apparatus in accordance with claim 1, wherein said means for contacting the stacks and discharging them from each of the pockets is mounted on said frame and moves therewith.

8. An apparatus in accordance with claim 7, wherein said means for contacting the stacks and discharging them from each of the pockets comprises means for moving a pusher through said pockets.

9. An apparatus in accordance with claim 8, wherein a separate pusher is provided for each of said pockets.

10. An apparatus in accordance with claim 9, wherein each pusher has a cam follower mounted on it, and wherein means are provided defining an endless cam track along which the follower of each pusher travels as the frame rotates.

11. An apparatus in accordance with claim 1, wherein each of said slots is defined by a pair of circumferentially Spaced plates lying generally in planes containing the axis of rotation of said frame, said plates being effective to maintain units in adjacent slots out of contact with one another.

12. An apparatus in accordance with claim 11, wherein at least a portion of each of said plates extends into the adjacent pocket so as to at least partially separate units in said pocket.

13. An apparatus in accordance with claim 1, wherein said means for delivering a unit to be stacked to each of said slots comprises a conveyor having a unit-supporting surface disposed so as to lie generally in the plane occupied by the slot to which a unit is delivered at the time of delivery thereto.

14. An apparatus in accordance with claim 13, wherein vacuum means are provided to retain each unit on said conveyor prior to delivery therefrom.

15. An apparatus in accordance with claim 4, wherein said shelf precludes movement of a unit from its slot into a pocket until the unit has been carried a short distance past a point essentially directly above the axis of rotation of said wheel so that the outer end of the slot in which the unit is carried is moved downwardly.

16. A method of arranging units in a stack comprising delivering the units one by one into slots extending radially inwardly from adjacent the periphery of a frame rotating about a fixed generally horizontal axis as the outer ends of the slots move upwardly past a point above the axis, maintaining the units of a predetermined circumferentially extending series of adjacent slots in those slots until the lead slot of the predetermined series reaches a predetermined position essentially directly above the axis of rotation, and thereafter allowing the units of the predetermined series to fall by gravity rapidly and successive- 1y one by one toward the axis of rotation as the lead slot of the predetermined series and those following reach the given position so as to thereby allow the units of the series to accumulate in a stack in a single pocket adjacent the axis of rotation.

17. A method in accordance with claim 16, including the step of discharging the stack of units onto a moving conveyor.

18. A method in accordance with claim 16, including the step of moistening a surface of each unit in engagement with a surface of an adjacent unit when the units are in stack form prior to delivery of the unit to the pocket to reduce shifting of the units relative to each other when in a stack.

19. A method in accordance with claim v16, including the step of subjecting the stack to a compressive force after it is discharged from the pocket, said force being generally normal to the surfaces of the units in engagement with surfaces of adjacent units.

References Cited UNITED STATES PATENTS 2,825,475 3/1958 Roberts.

2,940,750 6/1960 Mestre 27058 3,088,604 5/1963 Nilsson.

3,096,089 7/1963 Swenker et al 27058 X 3,221,902 12/1965 Young.

GERALD M. FORLENZA, Primary Examiner ROBERT J. SPAR, Assistant Examiner US. Cl. X.R.

232 3 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 9 Dated 29, 1969 Inventor(s) Edgar C. Olson a It is certified that error appears in the above-identified patfint and that said Letters Patent are hereby corrected as shown below:

A q F'Column 1, line 49, "receive" should be "receives";

line 50, "simultaneous" should be "simultaneously" Column 5, line 74, "The" is misspelled "An appropriate" should be Claim 4, line 51,

"An apparatus" 3 SIGNED AND SEALED APR 2 8 I970 Attest:

Edward M. Fletchcn In WILLIAM E- SGHUYLER, JR.

Gemissioner of Patents Attesting Officer 

